1. Field of the Invention
This invention relates generally to exercise equipment and, more particularly, to barbells having a pair of rotatable handles.
2. Description of the Prior Art
The use of an elongated barbell carrying one or more weight plates at each end is well known in the exercise field. The weight plates are held in place on the bar by a removable collar or other locking device. With one straight bar and a plurality of weight plates in a number of sizes, various muscles of the body can be readily exercised and developed.
In exercising certain muscles of the body, the hand position dictated by a straight bar is not ideal and other specialized bars have been developed. For example, a common triceps bar has a pair of spaced handles which are oriented transverse to the elongated bar carrying the weights. With the triceps bar, the hands are positioned in an opposed parallel relationship when the bar is gripped. A common curl bar, for exercising the biceps, has a pair of zig-zag-shaped handles which are oriented at opposed 45 degree angles to the bar carrying the weights. When the curl bar is held, a user's hand will be twisted symmetrically about the bar's center point. While the specially designed bars will comfortably and efficiently exercise the targeted muscle, a user must purchase several different bars and move the weight plates from one bar to another during a workout. Moreover, these bars all provide for a rigid positioning of the hands which remains fixed throughout a particular exercise.
A number of devices have been developed which overcome the problems with a straight bar and permit various muscles of the body to be efficiently exercised with a single bar. The devices shown in U.S. Pat. Nos. 3,384,370; 4,461,473; 4,629,184; 4,690,400 and United Kingdom patent application Ser. No. 2,186,500 show various arrangements of elongated bars which include a pair of rotatable handles which can be moved to a desired location. U.S. Pat. No. 1,333,005 shows a single rotatable handle connected to a weight. These devices also permit relative motion of the hands with respect to each other during the exercise. For example, in a supination motion during a bicep curling exercise, the hands are rotated from an initial position with the palms facing down or facing each other to a final position with the palms facing upward toward the user's chest. The reverse motion is referred to as pronation. Supination and pronation further increases muscle development during the exercise. Several of the prior art devices also provide for the application of additional force or resistance during the supination and pronation motions.
While providing for the relative hand motion desired during certain exercises, and the ability to move the handles to different positions in a single bar, most of the prior art devices are unnecessarily complicated in their construction, particularly when mechanisms for providing force or resistance during motion are induced. Moreover, even in the devices which provide for free rotational movement of the handles (such as in U.S. Pat. Nos. 3,384,370 and 4,690,400) the construction is far too complicated to manufacture inexpensively or is prone to breakage. This breakage problem is particularly acute when the exercise bar is used in conjunction with heavy weights.
Therefore, it is an object of the present invention to provide a weight lifting apparatus which includes a pair of rotatable handles, but which is uncomplicated in construction, which is relatively inexpensive to manufacture, and which is durable even when used with heavy weights